This invention relates to a method and apparatus for automatically cleaning a water pool, e.g., a swimming pool.
The prior art is replete with different types of automatic swimming pool cleaners. They include water surface cleaning devices which typically float at the water surface and can be moved across the water surface for cleaning, as by skimming. The prior art also shows pool wall surface cleaning devices which normally rest at the pool bottom but, which can be activated to move along the containment wall surface (which term should be understood to include primarily horizontal bottom and side primarily vertical portions) for wall cleaning, as by vacuuming and/or sweeping. Some prior art assemblies include both water surface cleaning and wall surface cleaning components tethered together.
Applicants"" U.S. Pat. No. 5,985,156 describes apparatus including a unitary body having (1) a level control subsystem for selectively moving the body to a position either proximate to the surface of the water pool or proximate to the interior surface of the containment wall, (2) a propulsion subsystem operable to selectively propel the body in either a forward or rearward direction, and (3) a cleaning subsystem operable in either a water surface cleaning mode (e.g., skimming or scooping) or a wall surface cleaning mode (e.g., vacuuming or sweeping). U.S. Pat. No. 5,985,156 discloses that these subsystems can be powered by hydraulic, pneumatic, or electric power sources and specifically describes hydraulic embodiments powered by positive and negative water pressure. Applicants"" U.S. Pat. Nos. 6,090,219 and 6,039,886 describe preferred cleaning systems powered by positive water pressure and negative water pressure (suction), respectively. The disclosures in applicants"" aforecited US patents are incorporated herein by reference.
The present invention is directed to automatic pool cleaning systems employing a unitary body configured to move through a pool to collect debris from adjacent to the pool containment wall surface and/or the pool water surface and more particularly to such systems which utilize electric power for propulsion and/or cleaning in combination with water suction power for cleaning and/or propulsion and/or electric generation.
Embodiments of the present invention are configured to derive electric power from either an onboard source or an external source. The onboard source can include a solar cell, an electric generator and/or a battery which can be charged from the solar cell or generator. Alternatively, the battery can be charged by causing the body to visit a charging station adjacent to the wall. The external source can comprise an electric wire extending to the body from the wall.
The body is preferably supported on some type of traction means, e.g., wheels. The electric power is used to drive an onboard electric motor to drive the traction means and/or a flow generator for propelling the body and/or cleaning. In addition to including electric propulsion means, preferred embodiments of the invention can also include an electrically powered steering means to facilitate movement of the body throughout the entire pool.
Embodiments of the present invention can be configured for cleaning operation either (1) solely adjacent to the wall or water surface or (2) selectively adjacent to the wall surface or adjacent to the water surface. Embodiments which are selectively operable adjacent to either the wall surface or water surface include a level control subsystem for producing a vertical force to cause the body to either ascend to the water surface or descend to the wall surface. In accordance with a preferred embodiment, the level control subsystem operates to selectively modify the buoyancy of the body, e.g., by filling or exhausting onboard air bags or expanding and compressing onboard air utilizing an electrically powered pump.
Embodiments of the invention can use either a heavier-than-water body or a lighter-than-water body. When a heavier-than-water body is used, the body in its quiescent or rest state typically sinks to the bottom portion of the pool containment wall. In an active state, the level control subsystem produces a vertical force component for lifting the body to the water surface. When a lighter-than-water body is used, the body in its quiescent state floats at a position proximate to the water surface. In an active state, the level control subsystem produces a vertical force component for causing the body to descend to the wall bottom portion. Embodiments of the invention are preferably configured to return the body to its quiescent state when electric power is terminated, whether by normal shut down or onboard by power depletion.
Embodiments of the present invention also employ a suction hose extending from a water outlet on the body to the pool wall for coupling the outlet to a water suction source, typically comprising the suction side of a main pool pump. The body defines a water flow path coupling one or more water inlets to the water outlet. The suction source functions to draw pool water (and water borne debris) into an inlet for passage through the flow path, outlet, and hose to the main pool pump and filter. A lower water inlet is located on the body in a position to collect water and debris from adjacent to the wall surface. An upper inlet can be located in a position to collect water and debris from adjacent to the water surface.
The aforementioned body outlet includes a hose fitting for coupling to the distal end of a suction hose. The hose fitting is preferably mounted to enable the orientation of the fitting (and the end of the suction hose coupled thereto) to be varied relative to the body. By varying the orientation of the hose fitting, the direction of drag forces on the body attributable to the hose will also vary to thereby increase the likelihood that the body will randomly traverse the entire pool area rather than being restricted to only a portion thereof. Moreover, to achieve even better pool area coverage, a steering means, e.g., electric motor, is preferably provided to continually or periodically vary the orientation of the hose fitting. In one disclosed embodiment, the hose fitting is mounted for pivotal positioning about an essentially vertical axis.
In an alternative embodiment, the fitting is mounted for pivotal positioning about an essentially horizontal axis. In this case, the fitting is moved to a first orientation for operation in the wall surface cleaning mode and to a second orientation for operation in the water surface cleaning mode. The respective orientations can be used to operate a valve to achieve optimum suction flows through the lower and upper inlets for cleaning in the respective wall surface and water surface modes.
In accordance with a still further feature of a preferred embodiment, redirect or repositioning means are preferably provided to facilitate extricating the body from situations in which it could get trapped behind an obstruction (e.g., ladder, steps, etc.) in the pool. A simple but effective repositioning technique utilizes the aforementioned steering means. That is, in addition to using the steering means to rotate the body through a normal range (i.e., minor arc) to achieve full pool coverage, the steering means can be selectively commanded to rotate the body by a more extreme degree (i.e., major arc) to move the body in a second direction different from the first direction normally induced by the propulsion means. Alternative repositioning techniques involve discharging a water flow having sideward and/or rearward thrust components, or twisting or tugging the suction hose to exert a force on the body.
In accordance with a still further feature of a preferred embodiment, an electrically driven flow generator, e.g., propeller, is provided on the body to generate a water flow to facilitate propulsion and/or steering/repositioning and/or cleaning.
In accordance with a further alternative arrangement, a turbine is mounted in the body so as to be driven by a suction flow between a water inlet and outlet. The turbine can be used to drive the propulsion means and in addition to drive an electric generator useful, e.g., for charging an onboard battery. The battery can drive a motor to assist in driving the propulsion means.
Embodiments of the invention preferably also include an onboard electronic controller for controlling the functioning (e.g., on, off, duration, etc.) of the aforementioned subsystems.